This invention relates to novel bicyclic diterpene compounds useful as PAF antagonists, antihistamines and antiinflammatory agents. The compounds are isolated from a PAF antagonist complex which is produced in fermentation under controlled conditions, using a biologically pure culture of the microorganism Phoma sp. SCF0592, ATCC 74077.
B. Karlsson et al. in Tetrahedron (1978), 34, 2349 disclose a bicyclic diterpene, verticillol represented by formula A ##STR1##
Verticillol is disclosed as a plant natural product, which follows the isoprene rule, isolated from the wood of Sciadopitys verticilla Sieb et Zucc (Taxodiaceae). This reference does not disclose any biological activity for verticillol and does not disclose or make obvious the bicyclic diterpene compounds of this invention.
Japanese Kokai J P 03,216,197 (91,216,197), published Sept. 24, 1991, discloses a bicyclic compound, phomactin B, represented by the formula B ##STR2##
Phomactin B is disclosed as a PAF antagonist which was produced by fermentation of Phoma sp. SANK 11486 (FERM BP-2598).
Neither reference discloses the compounds of this invention.